Dog doorbell



FIG. 1 is a perspective photographic view of a dog doorbell, showing my new design;

FIG. 2 is a front photographic view thereof;

FIG. 3 is a rear photographic view thereof;

FIG. 4 is a left side photographic view thereof;

FIG. 5 is a right side photographic view thereof;

FIG. 6 is a top plan photographic view thereof;

FIG. 7 is a bottom plan photographic view thereof; and,

FIG. 8 is another perspective photographic view thereof, viewed from a different direction for clarity of illustration. 

CLAIM The ornamental design for a dog doorbell, as shown and described. 